Mud pump valve



Feb; 28, 1939. G. c. DEAKlNs I MUD PUMP VALVE Filed Dec. 19, 1931 2 sheets-sheet 2 Patented F eb. 28, 1939 PATENT oFFicE MUD PUMP VALVE Grover C. Deakins, Anaheim, Calif., assig'nor, by

mesne assignments, to MacClatchie Manufac turing Company of California, Compton, Calif.,

a corporation of California Application December 19, 1931, serial No. 582,046

17 Claims.

My invention relates to valves of the character employed in mud pumps orother pumps adapted to pump fluid mixtures containing abrasive materals, and relates particularly to an improved form of such valve capable off'longer periods of uninterrupted use than valves which are at pres- `ent employed in pumps of this character.

as fine particles of rocks, quartz, or sand contained in the drilling fluid or mud, and therefore must be replaced after comparatively short periods of use. Such valves ordinarily-include a seat member consisting of an annular ring with a sealing seat near the upper end thereof and a spider structure across the lower portion thereof, and a valve element including a body of metal adapted to strike against the spider when the valve element is in lowered or Vrelatively closed position and a sealing member on the metal body adapted to engage the sealing face of the seat member and prevent leakage of fluid through the valve when the valve is in its closed position.

It is an object of my invention to provide a valve of the above character of simple construction yet being capable of giving a greater period of service than valves of complex structure.

It is an object of the invention to provide a valve having a seat member including an annular sealing'face or seat and a valve closure member having a circular or annular sealing member of rubber material adapted to enter the space enclosed by the annular sealing seat or face of the seat member and to be deformed by fluid pressure so as to expand against the sealing face of the seat member.

It is a further object of the invention to provide a valve of the above character in which the co-l operative parts are so'formed that the sealing member preferably wipes the sealing face clean as it moves into closed position, thereby reducing to a minimum the particles of abrasive material which may rest between the sealing member and the sealing face, the result thereof being that the wear between these parts is minimized and the useful life of the valve materially extended.

It is a further object of the invention to provide a valve which may be used for abrasive substances and which may be also employed inl pumps for circulating other fluids, such as crude oils.

. It is a still further object of the invention to seal the valve by a sealing member on the valve body having a peripheral annular engagement surface adapted to be received within an annular inwardly faced sealing wall surface of the valve seat, whereby the engagement surface is adapted. to be deformed radially outwardly for sealing engagement with the sealing wall surface. the seating movement of the valve body being limited by its engagement with a supporting surface of the seat member, and said supporting surface being at an angle to theA direction of opening and'closing movement of the valve appreciably greater than the angle of the sealing surface with relation to the direction of opening and closing movement of the Valve. The supporting surface thus takes the blow and relieves the sealing member of excessive wear asthe valve closes, and by its appreciable angle to the axis of the valve prevents radial distortion of the seat member or `swedging action such as might deform the seat or the valve body, while the smaller angle of the sealing surface with relation to the axis of the valve, insures a tight sealing engagement by radially deforming and confining the sealing member within the inwardly faced annular sealing wall surfac'e, rather than by merely pressing the sealing member against a cooperating surface lying at an appreciable angle to the axis of the valve.

Further objects and advantages of the invention will be made evident throughout the following part of the specification.

Referring to the drawings, which are for illustrative purposes only,

Fig. 1 is a partly sectioned elevational view showing a mud pump equipped with valves embodying my invention.

Fig. 2 is an enlarged fragmentary cross section showing one of the valves in closed position.

Fig. 3 is an enlarged fragmentary sectional view similar to Fig. 2 showing the valve in relatively open position.

Fig. 4 is a fragmentary sectional view showing an alternative manner in which clearance may be provided within the ,periphery of the sealing member of the valve.

Fig. 5 is a fragmentary sectional view showing an alternative form of the invention which is also suitable for pumping abrasive materials.

Fig. 6 is a fragmentary sectional view showing a form of my invention adapted for use in other types of pumps, such as oil pumps.

. Fig. 7 is a section on a plane represented by the line 1-1 of Fig. 2.

In Fig. 1 I show a reciprocating pump I0 having a pumping cylinder I i in which a piston I2 is reciprocated by a steam powered engine I3. The

rightward portion of the pump I is sectioned so as to show discharge valves I4 which are connected with the opposite ends of the cylinder II so that as the piston I2 is reciprocated, uid will be forced upwardly from the respective ends of the cylinder into an outlet chamber I5 which in mud pumpsis connected through .a rotary hose to the rotary drilling string.

. wardly from the annular wall I8 and a central hub 22 having an axial` opening 23 therein.`

As shown inl Fig. 2, the preferredembodiment of my improved valve I4 includes a seat ymember I6 and a valve body` or closure member' I1, which moves relative to the seat member I6. The seat member I6 includes an annular wall I8 and a support or spider which extends across the lower portion of the annular wall I8, this spider 20 com-A prising a number of radial arms2| extending in- Above the spider 20 the annular wall I8 is vformed with an annular sealing surface 24. This sealing surface is shown as preferably flaring out- Awardly and upwardly at a comparatively steep angle; or the sealing surface may have no taper but be cylindrical as will be later described with reference to Fig. 5, it being the steep angle of the sealing surface that greatly contributes to the improved operationand wear resisting qualities of my new valve. The valve body I1 is in the form of a metal enlargement having alower abutment area which includes abutment surfaces l adjacent both 'the axis-and the periphery of said enlargement and adapted, when the valve is closed, to engage the upper face of the hub 22 and theradial arms 2| which constitute the spider. The abutment surface of `the 'enlargement 25 which is adjacent the periphery thereof engages the abutment formed by the arms 2I adjacent land extending inwardly from the annular wall through which the stem 26 projects, the sealing member 30 being held in place on the body I1 by a flange member 32 which is held down against the upper face of the sealing member 30 by means of a pin 33 extended through the stem 26. The

sealing member 30 is of s uchexternal diameter that it will enter thespace enclosed by the surface 24 as the closure member I1 moves Afrom the open position in which it is shown in Fig. 3 tothe closed position in which it is shown in Fig. 2. As the member I1 moves to closed position fluid pressure within the chamber I5 is exerted downwardly against the annular upwardly directed surface 34 of the sealing member 30 exposed around the flange 32, such pressure `compressing the rubber or yieldable material of the peripheral'portion of the ysealing member 30 against the upper face of the body I1 and causing the periphery of the sealing member 3l! to .be expanded or.V deformed Vradially outwardly so as to be confined within and radially contact the surrounding annular wall surface 24. The sealing member 30 .is shown with a shallow peripheral groove 35 so as to f orm the semblance of a lip` 36, but for some uses satisfactory results may be obtained where the upper yface of the sealing member 30 left `flat.

A feature of the invention'is to make the diameter of the sealing member 30 of such measure relative to the diameter of the sealing surface 24 that not later than when the body I1 engages the spider 20 the fluid pressure in the chamber I5 will have caused the peripheral face 31 of the sealing member to engage the sealing surface 24, with the peripheral face 31 sealing against the sealingsurface 24 when-,the valve is closed.

Another feature of the invention which may be employed, is to make the diameter of the sealing member 30 of such measure relative to the diameter rof the sealing surface 24 that the fluid 'pressure in the chamber I5 will cause the periph eral face 31 of the sealing member to make wiping contact with the `surface 24 as the closure member I1 moves toward closed position. The sealing member 30 may be of such size that when the body I1, during its downward movement,

reaohesvthe position indicated by the dotted lines in Fig. 3, the fluid pressure in the `chamber I5 will cause the lower edge of the peripheral face 31 of the sealing member 30 to engage the upper edge of the wall surface 24. As the closure member I4 then continues downwardly toward fully closed position, such as shown in Fig. 2, the surfaces 24 and 31 wipe across one another and remove from each other much of the collected material. It may be Athat ne abrasive materials vwill remain on the surfaces 24 and 31, but the condition of the valve after it has been in use for a considerable period of time indicates that this wiping action at' least removes the larger particles of material which would prevent a sealing action between the periphery of the sealing member 30 and the wall surface 24. For illustration, as the closure member I1 moves to closed position, the lower peripheral corner 31 of the sealing member may wipe materials from the wall surface 24, and the upper annular corner 38 of the wall surface 24 may wipe materials from the face 31 of the .sealing member 30, leaving these surfaces in such condition that a practical seal will, result. ,For example, the seal formed is of such practical efficiency' that I have beenl able to employ a single valve structure continuously for a period of over ninety days, replacing the sealing member but once during this period. At the time of signing this application this valve is still in use with the second rubber or sealing member Another feature of the invention is to yieldably urge the sealing member 30into sealing engagef ment with wall surface 24', so that the sealing member may accommodate itself tov Wear of the metal parts of the valve structure without excessive wear of theresilient 'sealing member. For this purpose the flange member 32 is of such restricted diameter that the enlargement 25 as well as the sealing member 30 project appreciably radially beyond the flange member. An appreciable area of the upper surface of the sealing member is thus exposed to the fluid pressure in .chamber I5 for tightly seating the sealing member against wall surface 24, "and in the event of the metal parts'of the assembly being excessively worn so that the sealing member 30 is forced.

the outer peripheral portion of the sealing member 30 as will readily adapt it to its new seating position, with said flexing of the outer peripheral portion of the sealing member avoiding cutting through and destruction of the sealing member.

A further feature of my new construction is f terial dislodged from the surface 24 'as the valve body moves into closed position may collect. As

shown in Fig. 2, the space 40 is a continuous any 'nular space formed by reducing the diameter of the body I1 immediately below the sealing member 30. In Fig. 4 I show a space 40a having the same purpose which is formed by chamfering the upper peripheral edge of a body |1a which closely fits the lower portion of the Wall surface 24.

In Fig. 5 I show a form of my invention which is exactly the same as the valve shown in Figs.

2 and 3 with the exception that the sealing face or inwardly directed wall surface 24a is cylindrical for a greater part of its length and is slightly chamfered at the corner 38a. Corresponding to the surface 24a, the peripheral surface 31a of the sealing member 30a is cylindrical and may be of such diameter that responsive to fluid pressure, wiping engagement .between the surfaces- 24a and 31a will be accomplished as the closure member I1a moves into the closed position shown in Fig. 5, it being understood that upon reaching such closed position, fluid pressure against the sealing member causes radial expansion of its annular f ace 34a into tight sealing engagement with the surface 24a.

In Fig. 5 the wall surface 24a is shown cylindrical fora portion of its length and slightly flared at its upper end. In Figs. 2, 3, and 4, the wall surface 24'is shown comparatively steeply upwardly ared for the purpose of self-adjustment of the parts as the upper face of the support or spider wears down due to the repeated hammering of the body I1 thereagainst during the operation of the pump. Accordingly, in the preferred practice of my invention," the wall surface 24 may have such` a comparatively steep angle that the annular peripheral engagement surface of the sealing member is adapted to be radially expanded and confined within the annular wall surface 24, and moves relative to surface 24 in the direction of closing movement of the valve so as to permit ready dislodgement of abrasives rather than trapping the same between the surfaces 24-31; and the wall 24 may be flared at such a steep angle as to compensate for the wear between the surfaces 24' and 31 and between the bottom of the body l1 and the upper face of the support 20. As the stopping position of the body`l1 moves downwardly as the result of the last named wear, the sealing member, which has worn slightly, assumes a stopping position relative to a lower portion of the wall surface 24 of slightly'reduced diameter.

In Fig. 6 I show an alternative form of my valve having a seat member I6 of a form identical with the illustration thereof in Figs. 2, 3, and 4. In this form of the invention, however, the sealing member 30 is replaced by a dished or cupl shaped sealing member 50 having a circular wall vention isespecially designed for use in high presi sure `oil pumps or high pressure pumps for transferring other liquids. The same wiping action between the surfaces 24 and 53 of the members I6 and 50 may be accomplished, and the pounding effect due to the high pressure on the upper face of the movable valve part is received by the spider or support 20.

Another feature of the invention is that the supporting of the seat member which takes the blow when the valve closes, is at an appreciable angle to the direction of opening and closing movement of the valve, while the sealing engagel ment between surfaces 24-31 is at a slight angle to the direction of opening and closing movement. For example, as shown at Fig. 2, the surface 24 flares upwardly and radially outwardly at a steep angle, and the engagement surface 31 of the sealing member flares upwardly and radially outwardly at substantially the -same steep angle; while the upper surface ofhgpider 2l) which provides the abutment surface which takes the blow when the valve closes, is at an angle which is not nearly as steep.

Consequently the hammering blow of the closing valve is directed against the cooperating support of the seat member, at an angle which is at least a near approach to a right angle, so as to avoid swedging action or radial distortion of the seat member; and the sealing engagement at surfaces 24-31 is in a plane which is either parallel or close to parallel to the direction of movement of the valve, whereby material will readily dislodge from between the surfaces 24-31, and the sealing engagement is made' by radially outwardly deforming and confirming the sealing member within the annular wall 24. The arresting abutment and the sealing engagement atdifferent angles to the axis of the valve, with the arresting abutment at the greater angle, thus cooperate to dene a construction wherein the valve is seated without undue wear of the sealing member and without distortion of either the valve seat or the valve body, and with foreign material dislodged from between the body Aand seat, and the. sealing engagement resulting from radial expansion and confinement of the sealing member within an annular sealing wall of the valve seat.

Although I have herein shown and described my invention in simple and practical form, it is recognized that certain parts or elements thereof are representative of other parts, elements, or mechanisms which may be used in substantially the same manner to accomplish substantially the same results; therefore, it is to be understood that the invention is not to be hunted to the details disclosed herein but is to be accorded the full scope of the following claims.

I claim as my invention:

1. A lvalve of the character described, including: a seat member comprising an annular wall of short tubular form and a support consisting of an open-work structure extending across one end of said annular wall, the other end of said annular Wall providing an outwardly ared, inwardly faced sealing wall surface; a valve body adapted to move to and from said support, said valve body comprising a guide means and an enlargement adapted to engage said support; and an annular sealing member on the upper face of said enlargement having an outwardly flared resilient peripheral portion providing an annular engagement surface adapted to engage said wall surface as said valve body moves into engagement with said support and being of' such diameter relative to said wall surface as to engage said wall surface at a point before said enlargement engages said support'- and to have a wiping movement relative toy said wall surface as said enlargement moves from said point into engagement with said support, there being a space below said annular engagement surface to receive the wipings removed from said wall surface by said annular engagement surface, and the peripheral portion of the upper face of said sealing member being exposed to fluid pressure whereby such fluid pressure may deform the periphery of said sealing member outwardly to increase the pressure of the sealing engagement of l said sealing member with said wall surface.

2. A valve of the character described, including: a seat member comprising an annular wall of short tubular form and a support consisting of an open-work structure extending across one end of said annular wall, the other end of said annular wall providing an outwardly flared, inwardly faced sealing wall surface; a valve body adapted to move .to and from said support, said valvebody comprising a guide means and an enlargement adapted to engage said support; and

an annular sealing member on the upper face of said enlargement having an outwardly flared resilient peripheral portion providing an annular engagement surface adapted to engage said wall surface as said valve body moves into engagement with said support and being of such diameter relative to said wall surface as to engage said wall surface at a point before said enlargement engages said support and to have a wiping movement relative to said wall surface as said enlargement moves -from said point "into engagement with said support.

3. A valve of the character described including: a seat member comprising an annular wall and a' support below the upper end of theannular wall, the upper end of the annular wall providing an outwardlyflaring annular sealing surface; a valve body adapted tol move to and from the support, said valve body comprising a guide means and an enlargement adapted to engage the support; and an annular sealing member on the upper face of said enlargement having a resilient peripheral portion providing an annular engagement surface adapted to engage said annular sealing surface-as the valve body moves into engagement with the support and being of such diameter relative to the annular sealing surface as to engage said annular sealing surface at a point before said enlargement engages the support and to have wiping movement relative to the annular sealing surface as said enlargementmoves from said point into engagement with the support, there being a space below the annular engagement surface of sunlcient size to receivematerials wiped from the annular sealing surface by the'sealing member as said sealing member moves into closed position relative to the seat member.

4. A valve of the character described including: a seat member comprising an annular -wall and a support below the upper end of the annular wall, the upper end of the annular wall providing an outwardlyiiaring annular sealing surface; aA valvepbody adapted to move to and from the support; and an annular sealing member on the upper face of the body having an outwardly iiared resilient peripheral portion providing an annular engagement surface adapted to engage said annular sealing surface as the valve body moves into engagement with thel support and being of ysuch diameter relative tothe annular sealing surface as to engage said annular sealing surface at a point before the body engages the support and to have wiping movement relative to the annular sealing surface as the body moves from said point into engagement with the support, the peripheral portion of the upper face of the sealing member being exposed to fluid pressure whereby such uid pressure may deform the periphery of the sealing member to increase the pressure-of the sealing engagement of the sealing member with the annular sealing surface.

5. A valve of the character described, including: a seat member comprising an annular'wall and a support below the upper end of the annular wall, the upper end of the annular wall proy viding an outwardly iiaring annular sealing surinto engagement with the support; and a retain'- ing-member overlying the sealing member and of a diameter whereby the sealing member and the valve body project radially beyond the retaining member, so that the peripheral' portion of the sealing member may be flexed to accommodate it to the annular sealing surface and the upper face of said peripheral portion of the sealing member is exposed to -fluid `pressure whereby such uid pressure may deform the periphery of the sealing member to increase the pressure of the sealing engagement of the sealing member with the annular sealing surface.

6. In a valve; a seat member comprising an annular wall and an abutment surface below the upper end of and in the bore defined by the annular wall, the abutment surface being adjacent the axis of the annular wall, the upper end of the annular wall providing an outwardly flaring annular sealing surface; a valve body adapted to move to and from the abutment surface parallel to the axis of the annular wall, the abutment surface being adapted for engagement by the valve bodyat an angle to the axis of the annular wall appreciably greater than the angle of the annular sealing surface to said axis; andan annular sealing member on the valve body having a resilient peripheral portion providing a peripheral engagement surface normally,- flaring at substantially the same angle as that of the annular vsealing surface and of such diameter as to engage said annular sealing surface before the valve body engages the abutmentfsurface, the peripheral portion of the seal member being exposed to fluid pressure for deforming 'its 'liaring peripheral engagement'sux'fa'ce for sealing contact with thev annular sealing surface.

7. In a valve; a seat member comprising an annular wall and an abutment surface below the ing adapted for engagement by the valve body at an angle to the axis of the annular wall appreciably greater than the angle of the annular sealing surface to said axis; and an annular sealing member on the valve body having a'resilient peripheral portion providing a peripheral engagement surface normally flaring at substantially the same angle as that of the annular sealing surface, said peripheral portion ofthe sealf ing member being of such diameter and exposed to fluid pressure so that 'its flaring peripheral engagement surface engages the annular sealing surface before the valve body engages the abutment surface, and seals against the annular sealing surface when the valve is closed.

8. In a valve; a seat member comprising an annular wall and an abutment surface below the upper end of and in the bore defined by the an'- nular Wall, the upper end of the annular wall providing an outwardly flaring annular sealing surface; a valve body adapted to move to and from the abutment surface parallel to the axis of the annular wall, the abutment surface being adapted for engagement by the valve body at an-angle to the axis of the annular wall appreciably greater than the angle of the annular sealing surface to said axis; and an annular sealing member on. the valve body having a resilient peripheral portion providing a peripheral engagement surface normally flaring at substantially the same angle as that of the annular sealingy surface, said peripheral portion of the sealing member being of such diameter and exposedto fluid pressure so that its aring peripheral engagement surface engages the annular sealing surface before the valve body engages the abutment surface, and seals against the annular sealing surface -when the valveis closed; and there being space below said flaring peripheral engagement surface when the valve is closed, adapted to receive material dislodged from the annular sealing surface. i

9. In combination; a valve body adapted to move to and froma cooperating annular valve seat parallel to the axis of the valve body; and

an annular sealing member on the Valve body K havingl a resilientl peripheral portion providing a peripheral engagement surface normally flaring upwardly and outwardly, the Valve body having an abutment surface adapted to engage the valve seat, said abutment surface being at an angle to the axis of the valve body appreciably greater than the angle of said flaring peripheral engagement surface to said axis, the flaring peripheral engagementsurface being of such diameter as to engage the valve seat before the abutment surface of the valve body engages the valve seat, and the peripheral portion of the sealing member being exposed to fluid pressure for deforming its flaring peripheral engagement surface for sealing contact with the valve seat.

10. In combination; a valve body adapted to move to and from a cooperating annular valve seat parallel to the axis of the valve body; and an annular sealing member onithe upper face of the valve body having a resilient peripheral portion including an upstanding lip providing a peripheral engagement surface normally flaring upwardly and outwardly, the valve body having abutment surfaces adjacent both the periphery and the axis thereof adapted to engage the valve seat, saidabutment surface being at angles to 'the axis of the valve body appreciably greater than the angle of said flaring peripheral engagement surface to said axis, the flaring peripheral engagement surface being of such diameter as to engage the Valve seat by the time the abutment surfaces of the valve body engage the valve seat, and the lip of the sealing member being exposed to fluid pressure for deforming the flaring peripheral engagement surface of the sealing member for sealing contact with the `yalve seat.

11. In combination; a valve body adapted to move to and from a cooperating annular valve seat parallel to the axis of the valve body; and an annular sealing member on the valve body having a resilient peripheral portion providing a peripheral engagement surface normally flaring upwardly and outwardly, the valve body having an abutment surface adjacent the periphery thereof adapted to engage the valve seat, 'said abutment surface being at an angle to the axis of the valve body appreciably greater than the angle of said flaring peripheral engagement surface to said axis, the flaring peripheral engagement surface being of such diameter as to engage the valve seat by the time the abutment surface of the valve body engages the valve seat, and the peripheral portion of the sealing member being exposed to fluid pressure for deforming its flaring peripheral engagement surface for sealing contact with the valve seat.

l2. In combination; a valve body adapted to move to and from a cooperating annular valve seat parallel to the axis of the valve body; and an annular sealing member on the valve body having a resilient peripheral portion providing a peripheral engagement surface normally flaring upwardly and outwardly, the valve body having an abutment surface adjacent the axis thereof adapted to engage the valve seat, said abutment surface being at an angle to the axis of the valve body appreciably greater than the angle of said flaring peripheral engagement surface to said axis, the abutment surface being rigid throughout its area, the flaring peripheral engagement surface being of such diameter as to engage the valve seat by the time the abutment surface of the valve body engages the valve seat, and the peripheral portion of the sealing member being exposed to fluid pressure for deforming its flaring peripheral engagement surface for sealing contact with the valve seat.

13. In combination; a valve body adapted to move to and from a cooperating annular valve seat parallel to the axis of the valve body; and an annular sealing member on the valve body having a resilient peripheral portion providing a peripheral engagement surface normally flaring upwardly and outwardly, the valve body having an abutment surface adapted to engage the valve seat, said abutment surface being at an angle to the axis of the valve body appreciably greater than the angle of said flaring peripheral eng'agement surface to said axis, the abutment surface being rigid throughout its area, the flaring peripheral engagement surface being of such diameter as to engage the valve seat by the time the abutment surfacey of the valve body engages the valve seat, and the peripheral portion of the sealing member being exposed to fluid pressure for deforrning its flaring peripheral engagement surface for sealing contact with the valve seat.

14. In a valve; a seat member comprising an annular Wall and an abutmenty surface below the upper end of and in the bore defined by the annular wall, the abutment surface being adjacent the axis of the annular wall, the upper end of the annular wall providing an outwardly flaring annular sealing surface; a valve body adapted to move to and from the abutment surface parallel to the axis of the annular wall, the abutment surface being' adapted for engagement'by the valve body at an angle to the axisof the annular wall appreciably greater than the angle of thc annular sealing surface to said axis; an

annular' sealing member on the upper face of the valve body having a resilient peripheral portion including an upstanding lip providing a peripheral engagement surface normally flaring at substantially the same angle as that of the annular sealing surface and of such diameter as to engage the annular sealing surface by the time the valve body engages the abutment surface; and a retaining member overlying the sealing member and of a diameter less than that of the upstanding lip whereby said lip is exposed to fluid pressure for deforming its flaring peripheral engagement vsurface for sealing `contact with the annular sealing surface; there Ybeing space below said flaring peripheral engagement surface when the valve is closed, for reception of material dis` lodged from the annular sealing surface.

15. In a valve; a seat member comprising an annular wall and an abutment surface below the upper end of and in the bore defined by the annular wall, lthe upper end of the annular wall providing an outwardly flaring 'annular sealing surface; a valve body adapted to move to and from the abutment surface parallel to the axis of the annular wall, the abutment surface being adapted for engagement by the valve body at an angle to the axis of the annular wall appreciably greater than the angle of the annular'sealing sur- I face to said axis; an annular sealing member on the upper face of the valve body having a resilient peripheral portion providing a peripheral engagement surface normally flaring at substantially the same angle as thatof the annular sealing surface; and a retaining member overlying the sealing' member and of a diameter less than that of said peripheral portion of the sealing member, said'peripheral portion of the sealing member being of such diameter and exposed to fluid pressure s o that its flaring peripheral engagement surface engages the annular sealing surface by the time the'valve body engages the abutment surface, and seals against the annular sealing surface when the valveis closed; the

valve body and the sealing member when moved to closed position cooperating with the seat member to define a space for reception of material dislodged from the annular sealing surface.

l 16. In a Valve; a seat member comprising an annular wall and an abutment surface below the upper end of and in the bore dened by the annular wall, the upper 'end of the annular wall providing an outwardly flaring annular sealing surface; a valve body adapted to move to and from the abutment surface parallel to the axis of the annular wall, the abutment surface being adapted for engagement by the valve body at an angle to the axis of the annular wall appreciably greater than the angle of the annular sealing surface to said axis; `an annular sealing member on the upper face of the valve body having a resilient peripheral portion providing a peripheral engagement surfacenormally flaring at substantially the same angle as that of the annular sealing surface; and a retaining member overlying the sealing member and of a diameter less than that of said peripheral portion of the sealing member, said peripheral portion of the sealing member being of such diameter, and exposed to fluid pressure so that its flaring peripheral engagement surface engages the annular sealing surface by the time the valve body engages the abutment surface, and seals against the annular sealing surface when the valve is closed.

f 17. In combination; a valve body adapted to move to and from a cooperating annular valve seat parallel to the axis of the valve body; and an annular sealing member on the valve body having a resilient peripheral portion providing a peripheral engagement surface normally flaring upwardly and outwardly, the valve body having an abutment surface adjacent the axis thereof adapted to engage the valve seat, said abutment surface being at an angle to the axis of the valve body appreciably greater than the angle of said flaring peripheral engagement surface to said axis, the flaring peripheral engagement surface being of such diameter as to engage the valve seat before the abutment surface of'the valve body engages the valve seat; and there being space below said flaring peripheral engagement surface when the valve is closed, adapted to receive material dislodged from the valve seat.

` GROVER C. DEAKlNS. 

